It is standard as described in U.S. Pat. No. 3,098,671 of Moss, British patent No. 1,165,142 of Greenland, and German patent document No. 3,235,891 (based on Japanese P No. 56 153064 filed Sept. 29, 1989) of Miyamoto to provide a motor-vehicle door latch with a cutout that makes it impossible to open the door using the inside door handle and normally also to lock the door from the inside. Such a latch is typically provided on the rear doors so that a child cannot open the door and fall out or lock himself in the vehicle.
Typically the element that sets the child-safety cutout in the freeing or locking position is a lever that projects through or is exposed at a slot in the edge of the door. This slot is big enough to allow the lever to be shifted between its two positions and, therefore, constitutes a substantial opening into which water and dirt can get. In addition the projecting lever is easily actuated so that it can inadvertently or accidentally be set in the wrong position.